JPS60181312A - Regenerated cellulose fiber having high swelling property - Google Patents

Abstract

PURPOSE:To provide regenerated cellulose fiber produced from viscose added in advance with sodium sulfate, and having extremely high water-retainability and good colorability. CONSTITUTION:Sodium sulfate is added in the form of an aqueous solution to a viscose prepared by conventional process, and the viscose is used in the production of regenerated cellulose by conventional method. The objective regenerated cellulose having a primary swelling degree of >=150% can be obtained by this method.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing regenerated cellulose fibers having excellent water retention properties.

Regenerated cellulose fiber has a wide range of uses because it has better water retention than other fibers. This is because regenerated cellulose fibers have higher water retention than natural cellulose due to hydrated cellulose.9 However, the present inventor 5 and others conducted research on regenerated cellulose with even higher water retention, and found that when regenerating cellulose, The present invention was achieved by utilizing the generated gas.

When producing regenerated cellulose, if there are many impurities mixed in the raw material pulp, there is a phenomenon that the resulting fibers will have many flat threads. This is because a large amount of by-reactants are generated mainly in the sulfurization process due to the large amount of impurities mixed in the pulp, and the gas volume □ becomes larger than □ in viscose. A large amount of hydrogen sulfide is generated when the fiber is discharged, and the gaseous substance generated in the form of carbon disulfide through the main reaction is trapped in the fiber, causing the fiber to break down.

It is presumed that this is because the material first becomes hollow, which is then crimped and crushed into a flat shape.

The present inventors have discovered that if the gas generated in the fibers is deaerated before a large amount of gas remains in the fibers, the interior of the fibers will not become hollow and fibers with high water retention will be produced. I found it. That is, one aspect of the present invention is a viscose process regenerated cellulose fiber having a primary degree of 160% or more. This fiber is obtained by first spinning viscose containing sodium sulfate into a spinning bath, and then producing regenerated cellulose fiber by a conventional method. The degree of primary swelling of regenerated cellulose fibers produced by conventional methods without adding sodium sulfate to viscose is at most about 100%□, and the degree of dyeing is not high.

Here, the degree of In1 refers to the degree of swelling measured after producing regenerated cellulose fibers by a wet spinning method without going through the drying process (the degree of swelling measured after going through the drying process,
In other words, it is distinguished from the degree of secondary swelling). This degree of swelling is J
It can be measured in accordance with 7.25 of ISL-1015.

According to experiments conducted by the present inventors, the addition of sodium sulfate to viscose has an extremely effective effect on the production of fibers with a high degree of primary swelling, and the greater the amount added, the higher the degree of primary swelling.
It was found that fibers having a temperature of 11111 degrees were obtained. This is thought to be because the presence of sodium sulfate accelerates the coagulation of viscose and slows down the regeneration of fibers, so that the more sodium sulfate is present, the lower the crystallinity of the fibers becomes and the larger the amorphous region becomes. However, if the degree of blow swelling is high, it means that there are fewer crystalline parts in the fiber, so the strength will be lower accordingly, and those with an extremely high degree of primary mm (approximately 500% or more) will be of little practical use. Undesirable.

Also, the thicker the denier, the more gas is likely to be generated, and therefore, although it depends on the allowable strength reduction, it is preferable that the thicker the denier, the lower the sodium sulfate content in the viscose used. The more the better.

The method for adding sodium sulfate to viscose can be determined by taking into account the viscose production equipment to be employed and the N usage method, but it is preferable to add sodium sulfate to the process of dissolving xanthate or to the addition method. After preparing the course, add and dissolve in an aqueous solution.

The highly swellable regenerated cellulose fiber of the present invention exhibits extremely excellent dyeability, and the degree of dyeability is 1 ml! ! The higher the degree, the better it is.

The reason for the improvement in dyeability is thought to be that fibers with a high degree of primary swelling have a large amorphous region, which makes it easier for dyes to be adsorbed.

Obtained according to an example of the present invention. The relationship between the amount of sodium sulfate added and the primary moisture content of regenerated cellulose fibers, and the relationship between the amount of sodium sulfate added and the degree of dyeing are shown in Figures 1 and 2.
Shown below.

The present invention will be explained below with reference to Examples.

Example 1 Using a domestic valve with an α-cellulose content of 89%,
By common law! 71* total alkali 6.3%,
Sodium sulfate was added to viscose with a cellulose concentration of 8.7% as shown in Table 1, and then 1.5 denier regenerated cellulose fibers were produced using a conventional method. ll
Built.

Table 1 shows the effect of improving the degree of primary swelling and degree of dyeing by adding sodium sulfate.

- The degree of blow swelling and the degree of dyeing were measured in accordance with J15L1015.

Table 1 Example 2 22% m-acid was added to viscose with a total alkali of 6.3% and a cellulose concentration of 8.7% prepared by a conventional method using domestic pulp with an α-cellulose content of 89.2%. Add an aqueous sodium solution to viscose so that the sodium sulfate content is as shown in Table 2, and add this to IRtil.
lOg//-, zinc sulfate 13g/l, **f)'
)')b Spun into a spinning bath containing 340g1l of G, and then stretched and cut by a conventional method.

After scouring and drying, 3 denier regenerated cellulose fibers were obtained.

Table 2 shows the degree of primary swelling of the obtained a-fibers.

Table 2

[Brief explanation of the drawing]

FIG. 1 is a graph showing the relationship between the amount of sodium sulfate added and the degree of primary m fineness, and FIG. 2 is a graph showing the relationship between the amount of sodium sulfate added and the degree of staining.

Claims (1)

[Claims] Viscose process regenerated cellulose fiber with a primary swelling degree of 160% or more.